The Plague of Souls
by studlydursley69
Summary: It started with the darkest of magics and spread like wildfire, corrupting everything it touched. By the time anyone realized the danger there was almost nothing left to save. Now the savior of the Wizarding World once again stands alone, surrounded by shadows and a sickness that twists the soul itself.
1. Chapter 1

**Chapter 1: The Boy Who Lives**

If there was one thing Harry Potter had learned in the 16 miserable years of his life, it was how to take care of himself.

Wandering the empty streets of Hogsmeade, he reminded himself that he had faced far more difficult challenges battling basilisks and murderers, and that he had to do what he had always done- put aside his fear and hurt and act on instinct.

His stomach growled. He sighed wearily, looking over the signs of the shops. The Three Broomsticks stood out, memories of laughter and the sweet taste of butterbeer overwhelming him. Perhaps...

"No." He muttered firmly. There was nothing for him in there.

Most of the food in the pub would have gone bad by now. He could smell the rot from outside. The Hogs' Head was out of the question as well-hardly anything there was edible to begin with. Besides, it was dark inside. Too dark.

Still, he had come too far to return empty handed. And while it wasn't safe to go in, trying to find something was better than starving to death.

He gripped his wand tightly, reassuring himself. It had been weeks since it had been out of his hands, even when he ate and slept. It was the only thing he had to protect himself, and to avoid danger.

He wouldn't go into the pub, but Harry could still get what he needed.

"_Accio_ cans!" he cried, stepping to the side as two dozen pieces of metal flew out the window, smashing the glass into shattered fragments. The fresh snow cushioned the cans' impact and they remained intact. Harry examined them, finding beans, meat, potatoes and vegetables. All sealed and in perfect condition. He had hoped there'd be more.

Seeing the sun dip in the sky he hurried along and summoned whatever he thought would still be edible. Flour, sugar, salt, even pots and pans for cooking. He shoved it all in to the bulky burlap sack he had attempted to cast an extension charm on. The charm seemed to work for the most part, but by the time he was done the handle of a pot was digging into his back. And the featherweight charm barely worked at all. The weight of the supplies strained every muscle in his body. Harry wished he had paid more attention in charm's class.

'The liquor will have kept.' He thought wryly, attempting the featherweight charm once again before summoning bottles of butterbeer and firewhiskey into the bag. There was too much to do for Harry to fall into alcoholism at his tender age, but he needed a way to keep warm. The days were getting colder.

'Shorter too.' he noted. They hadn't passed the solstice yet, now matter how deep of a winter this was. Today was... early December. It had been at the Halloween Feast that things had started to go to hell, and it couldn't have been much more than a month since then. He had to move quickly.

He repaired the window, not wanting to leave a trace of his presence, and then hurried down the street to Honeydukes. He needed to stock up, and the sweets were likely in better shape then the healthier parts of his diet.

"_Lumos_." He whispered, as he came to the store window. The store was a mess- there had been a scuffle there. Bertie Bott's every flavoured beans were scattered across the floor, mixed with shards of glass; display counters had been smashed into pieces. But there were none of _them_.

Harry began greedily summoning everything that was intact, not willing to wait until they came back. If they figured out he was here they would starve him out, destroy everything he needed to survive. They would corner him. He couldn't have that.

As the sun began to set he considered that Hogsmeade may not be deserted- not for much longer anyway.

He hurried down the path to the Shrieking Shack, erasing his footsteps as he went. He had been safe there because it was abandoned- they knew nothing was there for them. The tunnel from Hogwarts to the shack was guarded by the Womping Willow, and only a handful of people knew about it - he was the last of them alive. Still, if the anyone else who knew the secret had come back... well, he had taken steps. He had booby trapped the tunnel with every muggle and magical trick he knew: pits, greek fire, stinging jinxes, stakes, tripwires and detection spells every other meter. And the entrance had been warded as heavily as the rest of the shack. He had become _obsessed_ with wards.

He was safe for now, so long as he kept his head down, but if Harry was survive he'd have to start thinking long term. There might still be scraps of food in the houses of the village, stones left unturned, but they would run out as well. If he lasted until spring he could start a garden- but even with concealment charms that might make his presence too visible.

Harry couldn't raid the castle kitchen either. There were too many dark places. Too many dead ends. Far too many of them.

'No.' he thought wistfully, he would never go back to Hogwarts. Happy memories didn't need any more tainting.

He would have to make his way to one of the nearby Muggle settlements. There would be more preserved food, but even more alluring than supplies was the chance of finding another person. Somewhere on an island of 60 million people there had to be someone else who was still making a go of it. Maybe they hadn't found everyone yet. Maybe there was still someone he could save. Maybe... maybe... maybe...

Harry clenched his fists until his knuckles were white. There was no use in getting his hopes up. Either he _was_ the only one left, or the others were hidden too well to be found by anyone.

'The _only_ Boy-Who-Lived.' he thought darkly. 'Some savior I turned out to be.'

He knew he was in Scotland, and he vaguely knew that half of Great Britain was within a day's reach of his broom. Floo was a death trap- no use teleporting into the belly of the beast. And, just his luck, the world had come to an end right before he learned to apparate. But Dobby had brought him his trunk- his map, his cloak, and his Firebolt. Distance was not the issue.

What was the issue was that if he went away from his sanctuary and was caught out at night-

Harry tensed, conscious of the last of the sun's rays vanishing. He was 100 meters away from the edge of his wards. He was weak from hunger, slower than normal. The heavy bag of food had slowed him even more. He quickened his pace, but he could feel the hair standing up on the back of his neck. One of them had been hiding here, waiting for night fall. And it had found him.

The hurried, clumsy footsteps were the only giveaway, the only way he could track its presence. There was no heartbeat, no breath, only the sound of movement.

Harry whipped around, free arm raised and guided by well honed instinct as he loosed his spell right as the revenant burst from the tree line.

"_Sectumsempra_!" he cried. Harry hit his mark, and was rewarded with the sound of flesh being rent from bone.

The creature's momentum was broken and it collapsed to the ground as Harry continued to move towards the shack. Harry cursed under his breath. He had missed the heart. He listened, he looked, he felt, and shook his head. Only one of them for now.

He always got one eye on the creature, black blood pooling in the snow as it lay, motionless. That was not the horrifying part. The part that always made Harry's heart stop was the moment when they got back up.

"Hiya Harry!" Colin Creevey called out, all of the old, senseless cheer still in his voice as he looked over Harry with a new kind of hunger. His robes were torn and his face had a haggard, ghoulish look to it. " I should have known you were still alive."

" I'm surprised, Colin." Harry said, delaying the inevitable. " I didn't think you'd have come back."

"I couldn't have done it without you." He said brightly, ignoring the wet sound of his left arm flopping in the wind, held to his body by only a few sinews. " Without your lessons and the DA, I wouldn't have been able to fight the others off long enough to turn. I would have been torn to pieces." Colin's ghoulish grin, his intense, sunken eyes, and the eager shivering of his body reminded Harry of a snake that had caught the scent of a rat. " But Harry, I'm going to need your help again."

" For the last time, Colin. I'm not giving you my autograph." Harry said, buying time as he edged closer and closer to the line that meant safety. He'd have to kill this creature, this shade that remained of Colin, and he'd have to dispose of the body so that no one else found it, and followed its trail.

"I know." Colin said good-naturedly. " But perhaps you can give me some food?" He pulled the robes over his stomach off to reveal jagged scars, the shape of human teeth, all across his torso. " You see, I'm still not strong enough to heal myself, and I haven't had anything to eat since Dennis." he grinned toothily. " A little flesh and blood ought to sort me out, though."

"Where is he? There wasn't enough of Dennis left to come back, was there?" Harry asked.

"No." Colin said guiltlessly. " Stripped to the bone after everyone got a bite of him."

Harry bit his lip until it bled. The coppery scent excited the beast, who took a step towards his prey. " I'm glad." Harry forced out. " He's at rest, now. And I'll put you to rest with him."

"Why don't you join him in my stomach instead!" Colin cried, lunging at his former hero.

"_Bombarda Maxima_!" Harry shouted, letting the explosive force of the spell push him and his cargo right over the line. The blast slammed into Colin and created a crater of smoke. Harry hoped that none of the others had been nearby. They would be drawn in like moths to a flame otherwise.

Colin's smoking corpse lunged forwards, innards hanging out, the wounds of his infection reopening from the force of the impact. His left arm was completely gone now, nothing but a stump, but he kept coming forward, growling.

But Harry had crossed his ward's barrier. He stared listlessly as the revenant charged. Just as Collin crossed the line he was pushed back smell of burnt meat filled Harry's lungs as blue fire enveloped Colin's good arm.

Colin recoiled, shrieking in pain and fear as he rolled about in the snow.

Fire, Harry had discovered, was one of the few ways of dealing with someone who had been infected. They hated light and caught fire easily- it was the only thing they feared. Short of destroying the heart or the head, flames were the best way of taking them down for good.

They weren't foolproof, though. Colin had stopped, dropped and rolled, and a puddle had formed, mixed with the ashes of his scorched skin. The shade looked at Harry, hatred in his eyes.

"You think you've won?!" Colin shouted. " I know where you are now! Once I tell the others, we'll find a way around anything to get at you. Every defense has a weakness. We'll torment you every night. You will never rest! You will never be safe! We'll feast!"

Harry sighed, and raised his wand, The Half Blood Prince's spell on his lips. He never got a chance to utter it.

An arm suddenly slammed through Colin's chest, piercing it like knife cutting through butter- right through his heart.

"_We_ won't be doing anything." A voice said calmly. The timbre was dark and feminine.

Colin convulsed before collapsing, body falling unto the line surrounding the Shrieking Shack and igniting. The newcomer stepped back from the flames, feral eyes glowing in the darkness, observing him.

Harry shuddered at the familiar, knowing smirk that adorned its features. Standing before him was the remnant of Hermione Granger.


	2. Chapter 2: The Girl Who Remains

**Chapter 2: The Girl Who Remains**

"_Merlin Hemione... your neck..."_

"_..Harry, listen to me. I'll buy you as much time as I can, but you need to get away NOW! Run as fast as you can, and don't look back."_

" _I can't leave you!"_

" _You can't save me! Just go!"_

The last conversation he had with the girl who had been his most trusted friend had haunted Harry's nightmares for weeks. Now, staring at her shade, it played on his head in an interminable loop.

Hermione kicked Colin's lifeless corpse closer to the Shrieking Shack, stepping back involuntarily as it burst into flame.

"Interesting." she muttered. Harry took her in. Her bushy brown hair was the same, and in the moonlight she looked painfully like the Hermione of the past. But her skin was a few shades too pale, her eyes far too cold, and he had never seen Hermione Granger with that kind of predatory smirk on her face.

Her features stayed the same as he raised his wand, though her body tensed as if ready to dodge in an instant. Harry's wand arm shook as he ran through every possible spell for the situation. Finally he settled on one.

"_Muffliato_!"

Harry had thought Hermione was jealous of him when he had used the Prince's book to get ahead in potions. Looking at her now he knew he had been wrong. He had never seen Hermione's face contorted in an expression anything like the one she wore now- yet he knew at once it was one of envy.

"Odd spell choice." The revenant muttered. Harry wondered idly if she had discarded her wand or still had it tucked away in her robes as a keepsake.

"I wouldn't want anyone else attracted by the noise. Why did you kill Colin?"

Hermione chuckled darkly. " The better question would be why we didn't kill the little pest sooner. The only reason I didn't arrange an accident for him when we were at Hogwarts was because my conscience would never have let me do something like that." She laughed a cold, joyless laugh. " I don't have that problem anymore."

"Then why haven't you attacked me?" Harry snarled.

Hermione laughed. " I'm hungry, not blind. I saw what happened to Colin, and while I don't care about the lives of others I still would rather keep my own. You've obviously set up some kind of autonomous defense...somehow..." The revenant lost interest in Harry for a moment, and he incredulously watched as she stared off into the distance, biting her lower lip as she once did when working through a complex problem. She whispered some things he couldn't catch before her eyes widened and she looked back at him.

" A runic array?" She muttered in surprise, casting a rock over the line to it engulfed in blue flame. She then glanced at the bag of supplies he clutched in his hands. " Keyed to your magic so anything that isn't you or on your person is incinerated if it crosses your ward line. As an amateur you only would have access to a handful of tools- the most basic grammar, maybe a hundred words. Not much room for error, hardly any sophistication. But also no loopholes for clever intruders to exploit. Simple, but effective. I'm impressed." Hermione laughed mirthlessly. " You've finally done your homework."

"Not much else to do anymore, is there?"Harry replied.

"It's a pity really." Hermione said. " You were always brilliant when you put your mind to something."

"And it took the end of the world for that something to be Ancient Runes."

The revenant smirked. Harry stared at her for a moment. He looked at the skin on the right side of her neck. There wasn't a mark on it. "Paying attention again?" Hermione teased. " Don't worry, I didn't go to the trouble of healing my wounds just to toss myself on this funeral pyre."

"If you know you can't get past the barrier, why are you here? Aren't you wasting your time?"

The revenant licked her lips.

"Would you believe me if I told you we were running out of food?"

The back of Harry's throat suddenly became very dry. "...What?" He forced out.

Hermione cocked her head. " Oh, its simple math, really. Using round numbers, there were about 10,000 witches and wizards in Britain and 60 million muggles. About half the wizarding population was either killed after turning or devoured before their bodies could turn at all. That leaves 5000 infected magical people with bottomless stomachs. Each of us can go through 50 people a day, easily, and you're well aware of how quickly a pack of us can strip a corpse. That's 250,000 people per day, conservatively. And that's only direct deaths from infected wizards- not factoring in all the elves, goblins, trolls, werewolves and other creatures who turned as well. An infected giant could consume several city blocks singlehandedly- though their movement is constrained by the need for large cover during the day.

"There are also the indirect deaths that need to be considered. How many muggles died during the panic, after we crippled their infrastructure and decapitated their government? How many killed themselves rather than end up in our stomachs? How many were bitten and escaped only to turn themselves? A creature without magic doesn't stay infected for long, but long enough to bite someone else before they completely degrade and turn more of the food supply into rotten meat." Hermione growled bitterly.

"I haven't had anything to eat in 4 days." She said. " And finally, after all that agonizing hunger, I come across a healthy, uninfected wizard to keep all to myself." The revenant tossed a twig across the barrier and recoiled when it caught flame. " More of us could force ourselves through the wards, eventually, but I'd be lucky to get a few scraps of you that way, and there's a very real chance I would die without getting a morsel. There aren't many meals left. I intend to savor you no matter how long it takes me to get you."

Harry gripped his wand so tightly it nearly snapped, blood pounding in his ears. 'Kill her, kill her, kill her!' a savage voice called in his heart. He hesitated.

... He couldn't do it, not while the monster was wearing her face, using her voice. He knew that she knew it too. He looked at her smile, all teeth, and shook indignantly at the perversion of that smile, at the horror that maw had unleashed on the world.

"You gave me estimates for the others. What about you? How many people?" Harry said evenly.

The shade grinned. " I don't know. How many loaves of bread have you eaten in your life?"

* * *

The interior of the Shrieking Shack was in rather good shape. Over the course of the last two weeks Harry had spent several sleepless nights transfiguring and repairing the broken down furniture and walls into something usable. He looked at the creature comforts around the house, from his extra clothes down to his bed, and grimaced, remembering the cost of getting them.

Dobby had responded to his call as soon as Harry had escaped Hogwarts, somehow avoiding infection. When he saw the state of the Shrieking Shack the house elf insisted on bringing in books, and chairs and even carpets from the Gryffindor common room, until one day he apparated into Hogwarts and didn't come back. Harry had checked the end of the tunnel the next day and found an elf's body with its head smashed by the Whomping Willow. It had tried to claw its way into the tunnel. He had pushed the misshapen corpse into the sun and watch it dissolve into ashes, and then booby trapped the tunnel with everything he had.

Of course, Hermione knew about the tunnel to the Shrieking Shack too. With any luck she'd sneak past the Willow's blows only to get caught in a well placed blast of Greek Fire. He wouldn't count on it, though. She had always been too clever for her own good- spotting details anyone else would have missed. Sooner or later she'd find a chink in his armor.

'Would it be so bad?' Harry thought sullenly. 'Everyone I've ever known and loved is either a ravenous undead cannibal or meat.' He pulled a bottle of Firewhiskey out of his enchanted sack, twisted off the cork and took a hearty chug straight from the bottle. His throat burned and he began coughing uncontrollably, his weakened body rebelling at his treatment. It didn't matter; at least this took his mind off the demoness prowling the perimeter of his home, and the memories of how everything went to hell.

It had only taken one bite to bring down all of Britain. From the spotty visions he had seen, Voldemort had been experimenting with captured Wizards and undead, trying to perfect another form of immortality. It backfired.

Before patient zero was put down it had bitten Voldemort and Wormtail. Voldemort was out of the picture. Harry didn't think anyone but he could kill Tom but he hadn't had any visions since the first night or seen any signs of the revenant Dark Lord, and if magic could turn the living into ravenous corpses he supposed anything was possible.

Wormtail had spread it to every other Death Eater in the hideout. They had spread it to everyone else.

The infection took a few minutes to set in, a few minutes where the victim still had control of their magic. Terrified witches and wizards would apparate to safety only to turn their sanctuary into a slaughterhouse. It had happened to countless homes, to Hogsmeade, Diagon Alley... and the Ministry. Britain had fallen into chaos within 24 hours, and the ICW had ordered a quarantine of the islands.

Harry had tried to warn Dumbledore as soon as he had seen the vision, before he was even fully conscious of what it meant, but by the time the Order had mobilized the situation had already spiraled out of control.

Hogwarts had lasted two weeks. No one could apparate in and Dumbledore had cut them from the floo network and raised the wards to full power. The surviving wizards had fallen back there to regroup as the Muggle population was left to the wolves. Eventually, somehow, one of them made it into the castle. That was that.

Harry put his wand to his temple, thinking. He had to... no. His hand shook. He wasn't capable of severing whatever bonds tethered the twisted fragments of Hermione to the world. It was _Hermione_. But so long as there was even a chance that there was a living person he could hurt he couldn't let himself be turned.

' You could stop it all with one spell.'

He tossed his wand aside furiously.

Something primal in him rebelled against the thought. No matter how bleak his life had become, and it had been bleak, he had never considered _that_ as an option. Gryffindors didn't take the coward's way out. So long as there was breath in his lungs he would fight. And if he did happen to get bitten at some point... well... he picked up his wand, pondering the best way to use his last moments of free will. " One spell." He said mirthlessly.

No sense casting it before then, though. He looked around the defenses of his little slice of sanity, walking into the training room where he could blast out magic to his hearts content and fuel his nascent wards. He had work to do.


End file.
